2 * Infrastructure for profiling code inserted by 'gcc -pg'.
4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5 * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
7 * Originally ported from the -rt patch by:
8 * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
10 * Based on code in the latency_tracer, that is:
12 * Copyright (C) 2004-2006 Ingo Molnar
13 * Copyright (C) 2004 William Lee Irwin III
16 #include <linux/stop_machine.h>
17 #include <linux/clocksource.h>
18 #include <linux/kallsyms.h>
19 #include <linux/seq_file.h>
20 #include <linux/suspend.h>
21 #include <linux/debugfs.h>
22 #include <linux/hardirq.h>
23 #include <linux/kthread.h>
24 #include <linux/uaccess.h>
25 #include <linux/kprobes.h>
26 #include <linux/ftrace.h>
27 #include <linux/sysctl.h>
28 #include <linux/ctype.h>
29 #include <linux/list.h>
30 #include <linux/hash.h>
32 #include <asm/ftrace.h>
36 #define FTRACE_WARN_ON(cond) \
42 #define FTRACE_WARN_ON_ONCE(cond) \
44 if (WARN_ON_ONCE(cond)) \
48 /* hash bits for specific function selection */
49 #define FTRACE_HASH_BITS 7
50 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
52 /* ftrace_enabled is a method to turn ftrace on or off */
53 int ftrace_enabled __read_mostly;
54 static int last_ftrace_enabled;
56 /* Quick disabling of function tracer. */
57 int function_trace_stop;
60 * ftrace_disabled is set when an anomaly is discovered.
61 * ftrace_disabled is much stronger than ftrace_enabled.
63 static int ftrace_disabled __read_mostly;
65 static DEFINE_MUTEX(ftrace_lock);
67 static struct ftrace_ops ftrace_list_end __read_mostly =
72 static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end;
73 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
74 ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
75 ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
77 static void ftrace_list_func(unsigned long ip, unsigned long parent_ip)
79 struct ftrace_ops *op = ftrace_list;
81 /* in case someone actually ports this to alpha! */
82 read_barrier_depends();
84 while (op != &ftrace_list_end) {
86 read_barrier_depends();
87 op->func(ip, parent_ip);
92 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip)
94 if (!test_tsk_trace_trace(current))
97 ftrace_pid_function(ip, parent_ip);
100 static void set_ftrace_pid_function(ftrace_func_t func)
102 /* do not set ftrace_pid_function to itself! */
103 if (func != ftrace_pid_func)
104 ftrace_pid_function = func;
108 * clear_ftrace_function - reset the ftrace function
110 * This NULLs the ftrace function and in essence stops
111 * tracing. There may be lag
113 void clear_ftrace_function(void)
115 ftrace_trace_function = ftrace_stub;
116 __ftrace_trace_function = ftrace_stub;
117 ftrace_pid_function = ftrace_stub;
120 #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
122 * For those archs that do not test ftrace_trace_stop in their
123 * mcount call site, we need to do it from C.
125 static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip)
127 if (function_trace_stop)
130 __ftrace_trace_function(ip, parent_ip);
134 static int __register_ftrace_function(struct ftrace_ops *ops)
136 ops->next = ftrace_list;
138 * We are entering ops into the ftrace_list but another
139 * CPU might be walking that list. We need to make sure
140 * the ops->next pointer is valid before another CPU sees
141 * the ops pointer included into the ftrace_list.
146 if (ftrace_enabled) {
149 if (ops->next == &ftrace_list_end)
152 func = ftrace_list_func;
154 if (ftrace_pid_trace) {
155 set_ftrace_pid_function(func);
156 func = ftrace_pid_func;
160 * For one func, simply call it directly.
161 * For more than one func, call the chain.
163 #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
164 ftrace_trace_function = func;
166 __ftrace_trace_function = func;
167 ftrace_trace_function = ftrace_test_stop_func;
174 static int __unregister_ftrace_function(struct ftrace_ops *ops)
176 struct ftrace_ops **p;
179 * If we are removing the last function, then simply point
180 * to the ftrace_stub.
182 if (ftrace_list == ops && ops->next == &ftrace_list_end) {
183 ftrace_trace_function = ftrace_stub;
184 ftrace_list = &ftrace_list_end;
188 for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next)
197 if (ftrace_enabled) {
198 /* If we only have one func left, then call that directly */
199 if (ftrace_list->next == &ftrace_list_end) {
200 ftrace_func_t func = ftrace_list->func;
202 if (ftrace_pid_trace) {
203 set_ftrace_pid_function(func);
204 func = ftrace_pid_func;
206 #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
207 ftrace_trace_function = func;
209 __ftrace_trace_function = func;
217 static void ftrace_update_pid_func(void)
221 mutex_lock(&ftrace_lock);
223 if (ftrace_trace_function == ftrace_stub)
226 func = ftrace_trace_function;
228 if (ftrace_pid_trace) {
229 set_ftrace_pid_function(func);
230 func = ftrace_pid_func;
232 if (func == ftrace_pid_func)
233 func = ftrace_pid_function;
236 #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
237 ftrace_trace_function = func;
239 __ftrace_trace_function = func;
243 mutex_unlock(&ftrace_lock);
246 /* set when tracing only a pid */
247 struct pid *ftrace_pid_trace;
248 static struct pid * const ftrace_swapper_pid = &init_struct_pid;
250 #ifdef CONFIG_DYNAMIC_FTRACE
252 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
253 # error Dynamic ftrace depends on MCOUNT_RECORD
256 static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
258 struct ftrace_func_hook {
259 struct hlist_node node;
260 struct ftrace_hook_ops *ops;
269 FTRACE_ENABLE_CALLS = (1 << 0),
270 FTRACE_DISABLE_CALLS = (1 << 1),
271 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
272 FTRACE_ENABLE_MCOUNT = (1 << 3),
273 FTRACE_DISABLE_MCOUNT = (1 << 4),
274 FTRACE_START_FUNC_RET = (1 << 5),
275 FTRACE_STOP_FUNC_RET = (1 << 6),
278 static int ftrace_filtered;
280 static LIST_HEAD(ftrace_new_addrs);
282 static DEFINE_MUTEX(ftrace_regex_lock);
285 struct ftrace_page *next;
287 struct dyn_ftrace records[];
290 #define ENTRIES_PER_PAGE \
291 ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace))
293 /* estimate from running different kernels */
294 #define NR_TO_INIT 10000
296 static struct ftrace_page *ftrace_pages_start;
297 static struct ftrace_page *ftrace_pages;
299 static struct dyn_ftrace *ftrace_free_records;
302 * This is a double for. Do not use 'break' to break out of the loop,
303 * you must use a goto.
305 #define do_for_each_ftrace_rec(pg, rec) \
306 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
308 for (_____i = 0; _____i < pg->index; _____i++) { \
309 rec = &pg->records[_____i];
311 #define while_for_each_ftrace_rec() \
315 #ifdef CONFIG_KPROBES
317 static int frozen_record_count;
319 static inline void freeze_record(struct dyn_ftrace *rec)
321 if (!(rec->flags & FTRACE_FL_FROZEN)) {
322 rec->flags |= FTRACE_FL_FROZEN;
323 frozen_record_count++;
327 static inline void unfreeze_record(struct dyn_ftrace *rec)
329 if (rec->flags & FTRACE_FL_FROZEN) {
330 rec->flags &= ~FTRACE_FL_FROZEN;
331 frozen_record_count--;
335 static inline int record_frozen(struct dyn_ftrace *rec)
337 return rec->flags & FTRACE_FL_FROZEN;
340 # define freeze_record(rec) ({ 0; })
341 # define unfreeze_record(rec) ({ 0; })
342 # define record_frozen(rec) ({ 0; })
343 #endif /* CONFIG_KPROBES */
345 static void ftrace_free_rec(struct dyn_ftrace *rec)
347 rec->ip = (unsigned long)ftrace_free_records;
348 ftrace_free_records = rec;
349 rec->flags |= FTRACE_FL_FREE;
352 void ftrace_release(void *start, unsigned long size)
354 struct dyn_ftrace *rec;
355 struct ftrace_page *pg;
356 unsigned long s = (unsigned long)start;
357 unsigned long e = s + size;
359 if (ftrace_disabled || !start)
362 mutex_lock(&ftrace_lock);
363 do_for_each_ftrace_rec(pg, rec) {
364 if ((rec->ip >= s) && (rec->ip < e))
365 ftrace_free_rec(rec);
366 } while_for_each_ftrace_rec();
367 mutex_unlock(&ftrace_lock);
370 static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
372 struct dyn_ftrace *rec;
374 /* First check for freed records */
375 if (ftrace_free_records) {
376 rec = ftrace_free_records;
378 if (unlikely(!(rec->flags & FTRACE_FL_FREE))) {
379 FTRACE_WARN_ON_ONCE(1);
380 ftrace_free_records = NULL;
384 ftrace_free_records = (void *)rec->ip;
385 memset(rec, 0, sizeof(*rec));
389 if (ftrace_pages->index == ENTRIES_PER_PAGE) {
390 if (!ftrace_pages->next) {
391 /* allocate another page */
393 (void *)get_zeroed_page(GFP_KERNEL);
394 if (!ftrace_pages->next)
397 ftrace_pages = ftrace_pages->next;
400 return &ftrace_pages->records[ftrace_pages->index++];
403 static struct dyn_ftrace *
404 ftrace_record_ip(unsigned long ip)
406 struct dyn_ftrace *rec;
411 rec = ftrace_alloc_dyn_node(ip);
417 list_add(&rec->list, &ftrace_new_addrs);
422 static void print_ip_ins(const char *fmt, unsigned char *p)
426 printk(KERN_CONT "%s", fmt);
428 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
429 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
432 static void ftrace_bug(int failed, unsigned long ip)
436 FTRACE_WARN_ON_ONCE(1);
437 pr_info("ftrace faulted on modifying ");
441 FTRACE_WARN_ON_ONCE(1);
442 pr_info("ftrace failed to modify ");
444 print_ip_ins(" actual: ", (unsigned char *)ip);
445 printk(KERN_CONT "\n");
448 FTRACE_WARN_ON_ONCE(1);
449 pr_info("ftrace faulted on writing ");
453 FTRACE_WARN_ON_ONCE(1);
454 pr_info("ftrace faulted on unknown error ");
461 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
463 unsigned long ip, fl;
464 unsigned long ftrace_addr;
466 ftrace_addr = (unsigned long)FTRACE_ADDR;
471 * If this record is not to be traced and
472 * it is not enabled then do nothing.
474 * If this record is not to be traced and
475 * it is enabled then disable it.
478 if (rec->flags & FTRACE_FL_NOTRACE) {
479 if (rec->flags & FTRACE_FL_ENABLED)
480 rec->flags &= ~FTRACE_FL_ENABLED;
484 } else if (ftrace_filtered && enable) {
489 fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED);
491 /* Record is filtered and enabled, do nothing */
492 if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED))
495 /* Record is not filtered or enabled, do nothing */
499 /* Record is not filtered but enabled, disable it */
500 if (fl == FTRACE_FL_ENABLED)
501 rec->flags &= ~FTRACE_FL_ENABLED;
503 /* Otherwise record is filtered but not enabled, enable it */
504 rec->flags |= FTRACE_FL_ENABLED;
506 /* Disable or not filtered */
509 /* if record is enabled, do nothing */
510 if (rec->flags & FTRACE_FL_ENABLED)
513 rec->flags |= FTRACE_FL_ENABLED;
517 /* if record is not enabled, do nothing */
518 if (!(rec->flags & FTRACE_FL_ENABLED))
521 rec->flags &= ~FTRACE_FL_ENABLED;
525 if (rec->flags & FTRACE_FL_ENABLED)
526 return ftrace_make_call(rec, ftrace_addr);
528 return ftrace_make_nop(NULL, rec, ftrace_addr);
531 static void ftrace_replace_code(int enable)
534 struct dyn_ftrace *rec;
535 struct ftrace_page *pg;
537 do_for_each_ftrace_rec(pg, rec) {
539 * Skip over free records and records that have
542 if (rec->flags & FTRACE_FL_FREE ||
543 rec->flags & FTRACE_FL_FAILED)
546 /* ignore updates to this record's mcount site */
547 if (get_kprobe((void *)rec->ip)) {
551 unfreeze_record(rec);
554 failed = __ftrace_replace_code(rec, enable);
555 if (failed && (rec->flags & FTRACE_FL_CONVERTED)) {
556 rec->flags |= FTRACE_FL_FAILED;
557 if ((system_state == SYSTEM_BOOTING) ||
558 !core_kernel_text(rec->ip)) {
559 ftrace_free_rec(rec);
561 ftrace_bug(failed, rec->ip);
563 } while_for_each_ftrace_rec();
567 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
574 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
577 rec->flags |= FTRACE_FL_FAILED;
583 static int __ftrace_modify_code(void *data)
587 if (*command & FTRACE_ENABLE_CALLS)
588 ftrace_replace_code(1);
589 else if (*command & FTRACE_DISABLE_CALLS)
590 ftrace_replace_code(0);
592 if (*command & FTRACE_UPDATE_TRACE_FUNC)
593 ftrace_update_ftrace_func(ftrace_trace_function);
595 if (*command & FTRACE_START_FUNC_RET)
596 ftrace_enable_ftrace_graph_caller();
597 else if (*command & FTRACE_STOP_FUNC_RET)
598 ftrace_disable_ftrace_graph_caller();
603 static void ftrace_run_update_code(int command)
605 stop_machine(__ftrace_modify_code, &command, NULL);
608 static ftrace_func_t saved_ftrace_func;
609 static int ftrace_start_up;
611 static void ftrace_startup_enable(int command)
613 if (saved_ftrace_func != ftrace_trace_function) {
614 saved_ftrace_func = ftrace_trace_function;
615 command |= FTRACE_UPDATE_TRACE_FUNC;
618 if (!command || !ftrace_enabled)
621 ftrace_run_update_code(command);
624 static void ftrace_startup(int command)
626 if (unlikely(ftrace_disabled))
630 command |= FTRACE_ENABLE_CALLS;
632 ftrace_startup_enable(command);
635 static void ftrace_shutdown(int command)
637 if (unlikely(ftrace_disabled))
641 if (!ftrace_start_up)
642 command |= FTRACE_DISABLE_CALLS;
644 if (saved_ftrace_func != ftrace_trace_function) {
645 saved_ftrace_func = ftrace_trace_function;
646 command |= FTRACE_UPDATE_TRACE_FUNC;
649 if (!command || !ftrace_enabled)
652 ftrace_run_update_code(command);
655 static void ftrace_startup_sysctl(void)
657 int command = FTRACE_ENABLE_MCOUNT;
659 if (unlikely(ftrace_disabled))
662 /* Force update next time */
663 saved_ftrace_func = NULL;
664 /* ftrace_start_up is true if we want ftrace running */
666 command |= FTRACE_ENABLE_CALLS;
668 ftrace_run_update_code(command);
671 static void ftrace_shutdown_sysctl(void)
673 int command = FTRACE_DISABLE_MCOUNT;
675 if (unlikely(ftrace_disabled))
678 /* ftrace_start_up is true if ftrace is running */
680 command |= FTRACE_DISABLE_CALLS;
682 ftrace_run_update_code(command);
685 static cycle_t ftrace_update_time;
686 static unsigned long ftrace_update_cnt;
687 unsigned long ftrace_update_tot_cnt;
689 static int ftrace_update_code(struct module *mod)
691 struct dyn_ftrace *p, *t;
694 start = ftrace_now(raw_smp_processor_id());
695 ftrace_update_cnt = 0;
697 list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) {
699 /* If something went wrong, bail without enabling anything */
700 if (unlikely(ftrace_disabled))
703 list_del_init(&p->list);
705 /* convert record (i.e, patch mcount-call with NOP) */
706 if (ftrace_code_disable(mod, p)) {
707 p->flags |= FTRACE_FL_CONVERTED;
713 stop = ftrace_now(raw_smp_processor_id());
714 ftrace_update_time = stop - start;
715 ftrace_update_tot_cnt += ftrace_update_cnt;
720 static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
722 struct ftrace_page *pg;
726 /* allocate a few pages */
727 ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL);
728 if (!ftrace_pages_start)
732 * Allocate a few more pages.
734 * TODO: have some parser search vmlinux before
735 * final linking to find all calls to ftrace.
737 * a) know how many pages to allocate.
739 * b) set up the table then.
741 * The dynamic code is still necessary for
745 pg = ftrace_pages = ftrace_pages_start;
747 cnt = num_to_init / ENTRIES_PER_PAGE;
748 pr_info("ftrace: allocating %ld entries in %d pages\n",
749 num_to_init, cnt + 1);
751 for (i = 0; i < cnt; i++) {
752 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
754 /* If we fail, we'll try later anyway */
765 FTRACE_ITER_FILTER = (1 << 0),
766 FTRACE_ITER_CONT = (1 << 1),
767 FTRACE_ITER_NOTRACE = (1 << 2),
768 FTRACE_ITER_FAILURES = (1 << 3),
769 FTRACE_ITER_PRINTALL = (1 << 4),
770 FTRACE_ITER_HASH = (1 << 5),
773 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
775 struct ftrace_iterator {
776 struct ftrace_page *pg;
780 unsigned char buffer[FTRACE_BUFF_MAX+1];
786 t_hash_next(struct seq_file *m, void *v, loff_t *pos)
788 struct ftrace_iterator *iter = m->private;
789 struct hlist_node *hnd = v;
790 struct hlist_head *hhd;
792 WARN_ON(!(iter->flags & FTRACE_ITER_HASH));
797 if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
800 hhd = &ftrace_func_hash[iter->hidx];
802 if (hlist_empty(hhd)) {
821 static void *t_hash_start(struct seq_file *m, loff_t *pos)
823 struct ftrace_iterator *iter = m->private;
826 iter->flags |= FTRACE_ITER_HASH;
828 return t_hash_next(m, p, pos);
831 static int t_hash_show(struct seq_file *m, void *v)
833 struct ftrace_func_hook *rec;
834 struct hlist_node *hnd = v;
835 char str[KSYM_SYMBOL_LEN];
837 rec = hlist_entry(hnd, struct ftrace_func_hook, node);
840 return rec->ops->print(m, rec->ip, rec->ops, rec->data);
842 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
843 seq_printf(m, "%s:", str);
845 kallsyms_lookup((unsigned long)rec->ops->func, NULL, NULL, NULL, str);
846 seq_printf(m, "%s", str);
849 seq_printf(m, ":%p", rec->data);
856 t_next(struct seq_file *m, void *v, loff_t *pos)
858 struct ftrace_iterator *iter = m->private;
859 struct dyn_ftrace *rec = NULL;
861 if (iter->flags & FTRACE_ITER_HASH)
862 return t_hash_next(m, v, pos);
866 if (iter->flags & FTRACE_ITER_PRINTALL)
870 if (iter->idx >= iter->pg->index) {
871 if (iter->pg->next) {
872 iter->pg = iter->pg->next;
879 rec = &iter->pg->records[iter->idx++];
880 if ((rec->flags & FTRACE_FL_FREE) ||
882 (!(iter->flags & FTRACE_ITER_FAILURES) &&
883 (rec->flags & FTRACE_FL_FAILED)) ||
885 ((iter->flags & FTRACE_ITER_FAILURES) &&
886 !(rec->flags & FTRACE_FL_FAILED)) ||
888 ((iter->flags & FTRACE_ITER_FILTER) &&
889 !(rec->flags & FTRACE_FL_FILTER)) ||
891 ((iter->flags & FTRACE_ITER_NOTRACE) &&
892 !(rec->flags & FTRACE_FL_NOTRACE))) {
901 static void *t_start(struct seq_file *m, loff_t *pos)
903 struct ftrace_iterator *iter = m->private;
906 mutex_lock(&ftrace_lock);
908 * For set_ftrace_filter reading, if we have the filter
909 * off, we can short cut and just print out that all
910 * functions are enabled.
912 if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) {
914 return t_hash_start(m, pos);
915 iter->flags |= FTRACE_ITER_PRINTALL;
920 if (iter->flags & FTRACE_ITER_HASH)
921 return t_hash_start(m, pos);
930 p = t_next(m, p, pos);
933 return t_hash_start(m, pos);
938 static void t_stop(struct seq_file *m, void *p)
940 mutex_unlock(&ftrace_lock);
943 static int t_show(struct seq_file *m, void *v)
945 struct ftrace_iterator *iter = m->private;
946 struct dyn_ftrace *rec = v;
947 char str[KSYM_SYMBOL_LEN];
949 if (iter->flags & FTRACE_ITER_HASH)
950 return t_hash_show(m, v);
952 if (iter->flags & FTRACE_ITER_PRINTALL) {
953 seq_printf(m, "#### all functions enabled ####\n");
960 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
962 seq_printf(m, "%s\n", str);
967 static struct seq_operations show_ftrace_seq_ops = {
975 ftrace_avail_open(struct inode *inode, struct file *file)
977 struct ftrace_iterator *iter;
980 if (unlikely(ftrace_disabled))
983 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
987 iter->pg = ftrace_pages_start;
989 ret = seq_open(file, &show_ftrace_seq_ops);
991 struct seq_file *m = file->private_data;
1001 int ftrace_avail_release(struct inode *inode, struct file *file)
1003 struct seq_file *m = (struct seq_file *)file->private_data;
1004 struct ftrace_iterator *iter = m->private;
1006 seq_release(inode, file);
1013 ftrace_failures_open(struct inode *inode, struct file *file)
1017 struct ftrace_iterator *iter;
1019 ret = ftrace_avail_open(inode, file);
1021 m = (struct seq_file *)file->private_data;
1022 iter = (struct ftrace_iterator *)m->private;
1023 iter->flags = FTRACE_ITER_FAILURES;
1030 static void ftrace_filter_reset(int enable)
1032 struct ftrace_page *pg;
1033 struct dyn_ftrace *rec;
1034 unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
1036 mutex_lock(&ftrace_lock);
1038 ftrace_filtered = 0;
1039 do_for_each_ftrace_rec(pg, rec) {
1040 if (rec->flags & FTRACE_FL_FAILED)
1042 rec->flags &= ~type;
1043 } while_for_each_ftrace_rec();
1044 mutex_unlock(&ftrace_lock);
1048 ftrace_regex_open(struct inode *inode, struct file *file, int enable)
1050 struct ftrace_iterator *iter;
1053 if (unlikely(ftrace_disabled))
1056 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
1060 mutex_lock(&ftrace_regex_lock);
1061 if ((file->f_mode & FMODE_WRITE) &&
1062 !(file->f_flags & O_APPEND))
1063 ftrace_filter_reset(enable);
1065 if (file->f_mode & FMODE_READ) {
1066 iter->pg = ftrace_pages_start;
1067 iter->flags = enable ? FTRACE_ITER_FILTER :
1068 FTRACE_ITER_NOTRACE;
1070 ret = seq_open(file, &show_ftrace_seq_ops);
1072 struct seq_file *m = file->private_data;
1077 file->private_data = iter;
1078 mutex_unlock(&ftrace_regex_lock);
1084 ftrace_filter_open(struct inode *inode, struct file *file)
1086 return ftrace_regex_open(inode, file, 1);
1090 ftrace_notrace_open(struct inode *inode, struct file *file)
1092 return ftrace_regex_open(inode, file, 0);
1096 ftrace_regex_read(struct file *file, char __user *ubuf,
1097 size_t cnt, loff_t *ppos)
1099 if (file->f_mode & FMODE_READ)
1100 return seq_read(file, ubuf, cnt, ppos);
1106 ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
1110 if (file->f_mode & FMODE_READ)
1111 ret = seq_lseek(file, offset, origin);
1113 file->f_pos = ret = 1;
1126 * (static function - no need for kernel doc)
1128 * Pass in a buffer containing a glob and this function will
1129 * set search to point to the search part of the buffer and
1130 * return the type of search it is (see enum above).
1131 * This does modify buff.
1133 * Returns enum type.
1134 * search returns the pointer to use for comparison.
1135 * not returns 1 if buff started with a '!'
1139 ftrace_setup_glob(char *buff, int len, char **search, int *not)
1141 int type = MATCH_FULL;
1144 if (buff[0] == '!') {
1153 for (i = 0; i < len; i++) {
1154 if (buff[i] == '*') {
1157 type = MATCH_END_ONLY;
1159 if (type == MATCH_END_ONLY)
1160 type = MATCH_MIDDLE_ONLY;
1162 type = MATCH_FRONT_ONLY;
1172 static int ftrace_match(char *str, char *regex, int len, int type)
1179 if (strcmp(str, regex) == 0)
1182 case MATCH_FRONT_ONLY:
1183 if (strncmp(str, regex, len) == 0)
1186 case MATCH_MIDDLE_ONLY:
1187 if (strstr(str, regex))
1190 case MATCH_END_ONLY:
1191 ptr = strstr(str, regex);
1192 if (ptr && (ptr[len] == 0))
1201 ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type)
1203 char str[KSYM_SYMBOL_LEN];
1205 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
1206 return ftrace_match(str, regex, len, type);
1209 static void ftrace_match_records(char *buff, int len, int enable)
1212 struct ftrace_page *pg;
1213 struct dyn_ftrace *rec;
1215 unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
1216 unsigned search_len;
1219 type = ftrace_setup_glob(buff, len, &search, ¬);
1221 search_len = strlen(search);
1223 mutex_lock(&ftrace_lock);
1224 do_for_each_ftrace_rec(pg, rec) {
1226 if (rec->flags & FTRACE_FL_FAILED)
1229 if (ftrace_match_record(rec, search, search_len, type)) {
1231 rec->flags &= ~flag;
1236 * Only enable filtering if we have a function that
1239 if (enable && (rec->flags & FTRACE_FL_FILTER))
1240 ftrace_filtered = 1;
1241 } while_for_each_ftrace_rec();
1242 mutex_unlock(&ftrace_lock);
1246 ftrace_match_module_record(struct dyn_ftrace *rec, char *mod,
1247 char *regex, int len, int type)
1249 char str[KSYM_SYMBOL_LEN];
1252 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
1254 if (!modname || strcmp(modname, mod))
1257 /* blank search means to match all funcs in the mod */
1259 return ftrace_match(str, regex, len, type);
1264 static void ftrace_match_module_records(char *buff, char *mod, int enable)
1266 char *search = buff;
1267 struct ftrace_page *pg;
1268 struct dyn_ftrace *rec;
1269 int type = MATCH_FULL;
1270 unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
1271 unsigned search_len = 0;
1274 /* blank or '*' mean the same */
1275 if (strcmp(buff, "*") == 0)
1278 /* handle the case of 'dont filter this module' */
1279 if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
1285 type = ftrace_setup_glob(buff, strlen(buff), &search, ¬);
1286 search_len = strlen(search);
1289 mutex_lock(&ftrace_lock);
1290 do_for_each_ftrace_rec(pg, rec) {
1292 if (rec->flags & FTRACE_FL_FAILED)
1295 if (ftrace_match_module_record(rec, mod,
1296 search, search_len, type)) {
1298 rec->flags &= ~flag;
1302 if (enable && (rec->flags & FTRACE_FL_FILTER))
1303 ftrace_filtered = 1;
1305 } while_for_each_ftrace_rec();
1306 mutex_unlock(&ftrace_lock);
1310 * We register the module command as a template to show others how
1311 * to register the a command as well.
1315 ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
1320 * cmd == 'mod' because we only registered this func
1321 * for the 'mod' ftrace_func_command.
1322 * But if you register one func with multiple commands,
1323 * you can tell which command was used by the cmd
1327 /* we must have a module name */
1331 mod = strsep(¶m, ":");
1335 ftrace_match_module_records(func, mod, enable);
1339 static struct ftrace_func_command ftrace_mod_cmd = {
1341 .func = ftrace_mod_callback,
1344 static int __init ftrace_mod_cmd_init(void)
1346 return register_ftrace_command(&ftrace_mod_cmd);
1348 device_initcall(ftrace_mod_cmd_init);
1351 function_trace_hook_call(unsigned long ip, unsigned long parent_ip)
1353 struct ftrace_func_hook *entry;
1354 struct hlist_head *hhd;
1355 struct hlist_node *n;
1359 key = hash_long(ip, FTRACE_HASH_BITS);
1361 hhd = &ftrace_func_hash[key];
1363 if (hlist_empty(hhd))
1367 * Disable preemption for these calls to prevent a RCU grace
1368 * period. This syncs the hash iteration and freeing of items
1369 * on the hash. rcu_read_lock is too dangerous here.
1371 resched = ftrace_preempt_disable();
1372 hlist_for_each_entry_rcu(entry, n, hhd, node) {
1373 if (entry->ip == ip)
1374 entry->ops->func(ip, parent_ip, &entry->data);
1376 ftrace_preempt_enable(resched);
1379 static struct ftrace_ops trace_hook_ops __read_mostly =
1381 .func = function_trace_hook_call,
1384 static int ftrace_hook_registered;
1386 static void __enable_ftrace_function_hook(void)
1390 if (ftrace_hook_registered)
1393 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
1394 struct hlist_head *hhd = &ftrace_func_hash[i];
1398 /* Nothing registered? */
1399 if (i == FTRACE_FUNC_HASHSIZE)
1402 __register_ftrace_function(&trace_hook_ops);
1404 ftrace_hook_registered = 1;
1407 static void __disable_ftrace_function_hook(void)
1411 if (!ftrace_hook_registered)
1414 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
1415 struct hlist_head *hhd = &ftrace_func_hash[i];
1420 /* no more funcs left */
1421 __unregister_ftrace_function(&trace_hook_ops);
1423 ftrace_hook_registered = 0;
1427 static void ftrace_free_entry_rcu(struct rcu_head *rhp)
1429 struct ftrace_func_hook *entry =
1430 container_of(rhp, struct ftrace_func_hook, rcu);
1432 if (entry->ops->free)
1433 entry->ops->free(&entry->data);
1439 register_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
1442 struct ftrace_func_hook *entry;
1443 struct ftrace_page *pg;
1444 struct dyn_ftrace *rec;
1450 type = ftrace_setup_glob(glob, strlen(glob), &search, ¬);
1451 len = strlen(search);
1453 /* we do not support '!' for function hooks */
1457 mutex_lock(&ftrace_lock);
1458 do_for_each_ftrace_rec(pg, rec) {
1460 if (rec->flags & FTRACE_FL_FAILED)
1463 if (!ftrace_match_record(rec, search, len, type))
1466 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1468 /* If we did not hook to any, then return error */
1479 * The caller might want to do something special
1480 * for each function we find. We call the callback
1481 * to give the caller an opportunity to do so.
1483 if (ops->callback) {
1484 if (ops->callback(rec->ip, &entry->data) < 0) {
1485 /* caller does not like this func */
1492 entry->ip = rec->ip;
1494 key = hash_long(entry->ip, FTRACE_HASH_BITS);
1495 hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
1497 } while_for_each_ftrace_rec();
1498 __enable_ftrace_function_hook();
1501 mutex_unlock(&ftrace_lock);
1512 __unregister_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
1513 void *data, int flags)
1515 struct ftrace_func_hook *entry;
1516 struct hlist_node *n, *tmp;
1517 char str[KSYM_SYMBOL_LEN];
1518 int type = MATCH_FULL;
1522 if (glob && (strcmp(glob, "*") || !strlen(glob)))
1527 type = ftrace_setup_glob(glob, strlen(glob), &search, ¬);
1528 len = strlen(search);
1530 /* we do not support '!' for function hooks */
1535 mutex_lock(&ftrace_lock);
1536 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
1537 struct hlist_head *hhd = &ftrace_func_hash[i];
1539 hlist_for_each_entry_safe(entry, n, tmp, hhd, node) {
1541 /* break up if statements for readability */
1542 if ((flags & HOOK_TEST_FUNC) && entry->ops != ops)
1545 if ((flags & HOOK_TEST_DATA) && entry->data != data)
1548 /* do this last, since it is the most expensive */
1550 kallsyms_lookup(entry->ip, NULL, NULL,
1552 if (!ftrace_match(str, glob, len, type))
1556 hlist_del(&entry->node);
1557 call_rcu(&entry->rcu, ftrace_free_entry_rcu);
1560 __disable_ftrace_function_hook();
1561 mutex_unlock(&ftrace_lock);
1565 unregister_ftrace_function_hook(char *glob, struct ftrace_hook_ops *ops,
1568 __unregister_ftrace_function_hook(glob, ops, data,
1569 HOOK_TEST_FUNC | HOOK_TEST_DATA);
1573 unregister_ftrace_function_hook_func(char *glob, struct ftrace_hook_ops *ops)
1575 __unregister_ftrace_function_hook(glob, ops, NULL, HOOK_TEST_FUNC);
1578 void unregister_ftrace_function_hook_all(char *glob)
1580 __unregister_ftrace_function_hook(glob, NULL, NULL, 0);
1583 static LIST_HEAD(ftrace_commands);
1584 static DEFINE_MUTEX(ftrace_cmd_mutex);
1586 int register_ftrace_command(struct ftrace_func_command *cmd)
1588 struct ftrace_func_command *p;
1591 mutex_lock(&ftrace_cmd_mutex);
1592 list_for_each_entry(p, &ftrace_commands, list) {
1593 if (strcmp(cmd->name, p->name) == 0) {
1598 list_add(&cmd->list, &ftrace_commands);
1600 mutex_unlock(&ftrace_cmd_mutex);
1605 int unregister_ftrace_command(struct ftrace_func_command *cmd)
1607 struct ftrace_func_command *p, *n;
1610 mutex_lock(&ftrace_cmd_mutex);
1611 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
1612 if (strcmp(cmd->name, p->name) == 0) {
1614 list_del_init(&p->list);
1619 mutex_unlock(&ftrace_cmd_mutex);
1624 static int ftrace_process_regex(char *buff, int len, int enable)
1626 struct ftrace_func_command *p;
1627 char *func, *command, *next = buff;
1630 func = strsep(&next, ":");
1633 ftrace_match_records(func, len, enable);
1639 command = strsep(&next, ":");
1641 mutex_lock(&ftrace_cmd_mutex);
1642 list_for_each_entry(p, &ftrace_commands, list) {
1643 if (strcmp(p->name, command) == 0) {
1644 ret = p->func(func, command, next, enable);
1649 mutex_unlock(&ftrace_cmd_mutex);
1655 ftrace_regex_write(struct file *file, const char __user *ubuf,
1656 size_t cnt, loff_t *ppos, int enable)
1658 struct ftrace_iterator *iter;
1663 if (!cnt || cnt < 0)
1666 mutex_lock(&ftrace_regex_lock);
1668 if (file->f_mode & FMODE_READ) {
1669 struct seq_file *m = file->private_data;
1672 iter = file->private_data;
1675 iter->flags &= ~FTRACE_ITER_CONT;
1676 iter->buffer_idx = 0;
1679 ret = get_user(ch, ubuf++);
1685 if (!(iter->flags & ~FTRACE_ITER_CONT)) {
1686 /* skip white space */
1687 while (cnt && isspace(ch)) {
1688 ret = get_user(ch, ubuf++);
1696 file->f_pos += read;
1701 iter->buffer_idx = 0;
1704 while (cnt && !isspace(ch)) {
1705 if (iter->buffer_idx < FTRACE_BUFF_MAX)
1706 iter->buffer[iter->buffer_idx++] = ch;
1711 ret = get_user(ch, ubuf++);
1720 iter->buffer[iter->buffer_idx] = 0;
1721 ret = ftrace_process_regex(iter->buffer,
1722 iter->buffer_idx, enable);
1725 iter->buffer_idx = 0;
1727 iter->flags |= FTRACE_ITER_CONT;
1730 file->f_pos += read;
1734 mutex_unlock(&ftrace_regex_lock);
1740 ftrace_filter_write(struct file *file, const char __user *ubuf,
1741 size_t cnt, loff_t *ppos)
1743 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
1747 ftrace_notrace_write(struct file *file, const char __user *ubuf,
1748 size_t cnt, loff_t *ppos)
1750 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
1754 ftrace_set_regex(unsigned char *buf, int len, int reset, int enable)
1756 if (unlikely(ftrace_disabled))
1759 mutex_lock(&ftrace_regex_lock);
1761 ftrace_filter_reset(enable);
1763 ftrace_match_records(buf, len, enable);
1764 mutex_unlock(&ftrace_regex_lock);
1768 * ftrace_set_filter - set a function to filter on in ftrace
1769 * @buf - the string that holds the function filter text.
1770 * @len - the length of the string.
1771 * @reset - non zero to reset all filters before applying this filter.
1773 * Filters denote which functions should be enabled when tracing is enabled.
1774 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
1776 void ftrace_set_filter(unsigned char *buf, int len, int reset)
1778 ftrace_set_regex(buf, len, reset, 1);
1782 * ftrace_set_notrace - set a function to not trace in ftrace
1783 * @buf - the string that holds the function notrace text.
1784 * @len - the length of the string.
1785 * @reset - non zero to reset all filters before applying this filter.
1787 * Notrace Filters denote which functions should not be enabled when tracing
1788 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
1791 void ftrace_set_notrace(unsigned char *buf, int len, int reset)
1793 ftrace_set_regex(buf, len, reset, 0);
1797 ftrace_regex_release(struct inode *inode, struct file *file, int enable)
1799 struct seq_file *m = (struct seq_file *)file->private_data;
1800 struct ftrace_iterator *iter;
1802 mutex_lock(&ftrace_regex_lock);
1803 if (file->f_mode & FMODE_READ) {
1806 seq_release(inode, file);
1808 iter = file->private_data;
1810 if (iter->buffer_idx) {
1812 iter->buffer[iter->buffer_idx] = 0;
1813 ftrace_match_records(iter->buffer, iter->buffer_idx, enable);
1816 mutex_lock(&ftrace_lock);
1817 if (ftrace_start_up && ftrace_enabled)
1818 ftrace_run_update_code(FTRACE_ENABLE_CALLS);
1819 mutex_unlock(&ftrace_lock);
1822 mutex_unlock(&ftrace_regex_lock);
1827 ftrace_filter_release(struct inode *inode, struct file *file)
1829 return ftrace_regex_release(inode, file, 1);
1833 ftrace_notrace_release(struct inode *inode, struct file *file)
1835 return ftrace_regex_release(inode, file, 0);
1838 static struct file_operations ftrace_avail_fops = {
1839 .open = ftrace_avail_open,
1841 .llseek = seq_lseek,
1842 .release = ftrace_avail_release,
1845 static struct file_operations ftrace_failures_fops = {
1846 .open = ftrace_failures_open,
1848 .llseek = seq_lseek,
1849 .release = ftrace_avail_release,
1852 static struct file_operations ftrace_filter_fops = {
1853 .open = ftrace_filter_open,
1854 .read = ftrace_regex_read,
1855 .write = ftrace_filter_write,
1856 .llseek = ftrace_regex_lseek,
1857 .release = ftrace_filter_release,
1860 static struct file_operations ftrace_notrace_fops = {
1861 .open = ftrace_notrace_open,
1862 .read = ftrace_regex_read,
1863 .write = ftrace_notrace_write,
1864 .llseek = ftrace_regex_lseek,
1865 .release = ftrace_notrace_release,
1868 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1870 static DEFINE_MUTEX(graph_lock);
1872 int ftrace_graph_count;
1873 unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
1876 g_next(struct seq_file *m, void *v, loff_t *pos)
1878 unsigned long *array = m->private;
1883 if (index >= ftrace_graph_count)
1886 return &array[index];
1889 static void *g_start(struct seq_file *m, loff_t *pos)
1893 mutex_lock(&graph_lock);
1895 p = g_next(m, p, pos);
1900 static void g_stop(struct seq_file *m, void *p)
1902 mutex_unlock(&graph_lock);
1905 static int g_show(struct seq_file *m, void *v)
1907 unsigned long *ptr = v;
1908 char str[KSYM_SYMBOL_LEN];
1913 kallsyms_lookup(*ptr, NULL, NULL, NULL, str);
1915 seq_printf(m, "%s\n", str);
1920 static struct seq_operations ftrace_graph_seq_ops = {
1928 ftrace_graph_open(struct inode *inode, struct file *file)
1932 if (unlikely(ftrace_disabled))
1935 mutex_lock(&graph_lock);
1936 if ((file->f_mode & FMODE_WRITE) &&
1937 !(file->f_flags & O_APPEND)) {
1938 ftrace_graph_count = 0;
1939 memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
1942 if (file->f_mode & FMODE_READ) {
1943 ret = seq_open(file, &ftrace_graph_seq_ops);
1945 struct seq_file *m = file->private_data;
1946 m->private = ftrace_graph_funcs;
1949 file->private_data = ftrace_graph_funcs;
1950 mutex_unlock(&graph_lock);
1956 ftrace_graph_read(struct file *file, char __user *ubuf,
1957 size_t cnt, loff_t *ppos)
1959 if (file->f_mode & FMODE_READ)
1960 return seq_read(file, ubuf, cnt, ppos);
1966 ftrace_set_func(unsigned long *array, int idx, char *buffer)
1968 char str[KSYM_SYMBOL_LEN];
1969 struct dyn_ftrace *rec;
1970 struct ftrace_page *pg;
1974 if (ftrace_disabled)
1977 mutex_lock(&ftrace_lock);
1978 do_for_each_ftrace_rec(pg, rec) {
1980 if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE))
1983 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
1984 if (strcmp(str, buffer) == 0) {
1985 /* Return 1 if we add it to the array */
1987 for (j = 0; j < idx; j++)
1988 if (array[j] == rec->ip) {
1993 array[idx] = rec->ip;
1996 } while_for_each_ftrace_rec();
1998 mutex_unlock(&ftrace_lock);
2000 return found ? 0 : -EINVAL;
2004 ftrace_graph_write(struct file *file, const char __user *ubuf,
2005 size_t cnt, loff_t *ppos)
2007 unsigned char buffer[FTRACE_BUFF_MAX+1];
2008 unsigned long *array;
2014 if (!cnt || cnt < 0)
2017 mutex_lock(&graph_lock);
2019 if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) {
2024 if (file->f_mode & FMODE_READ) {
2025 struct seq_file *m = file->private_data;
2028 array = file->private_data;
2030 ret = get_user(ch, ubuf++);
2036 /* skip white space */
2037 while (cnt && isspace(ch)) {
2038 ret = get_user(ch, ubuf++);
2051 while (cnt && !isspace(ch)) {
2052 if (index < FTRACE_BUFF_MAX)
2053 buffer[index++] = ch;
2058 ret = get_user(ch, ubuf++);
2066 /* we allow only one at a time */
2067 ret = ftrace_set_func(array, ftrace_graph_count, buffer);
2071 ftrace_graph_count++;
2073 file->f_pos += read;
2077 mutex_unlock(&graph_lock);
2082 static const struct file_operations ftrace_graph_fops = {
2083 .open = ftrace_graph_open,
2084 .read = ftrace_graph_read,
2085 .write = ftrace_graph_write,
2087 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
2089 static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
2091 struct dentry *entry;
2093 entry = debugfs_create_file("available_filter_functions", 0444,
2094 d_tracer, NULL, &ftrace_avail_fops);
2096 pr_warning("Could not create debugfs "
2097 "'available_filter_functions' entry\n");
2099 entry = debugfs_create_file("failures", 0444,
2100 d_tracer, NULL, &ftrace_failures_fops);
2102 pr_warning("Could not create debugfs 'failures' entry\n");
2104 entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer,
2105 NULL, &ftrace_filter_fops);
2107 pr_warning("Could not create debugfs "
2108 "'set_ftrace_filter' entry\n");
2110 entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer,
2111 NULL, &ftrace_notrace_fops);
2113 pr_warning("Could not create debugfs "
2114 "'set_ftrace_notrace' entry\n");
2116 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
2117 entry = debugfs_create_file("set_graph_function", 0444, d_tracer,
2119 &ftrace_graph_fops);
2121 pr_warning("Could not create debugfs "
2122 "'set_graph_function' entry\n");
2123 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
2128 static int ftrace_convert_nops(struct module *mod,
2129 unsigned long *start,
2134 unsigned long flags;
2136 mutex_lock(&ftrace_lock);
2139 addr = ftrace_call_adjust(*p++);
2141 * Some architecture linkers will pad between
2142 * the different mcount_loc sections of different
2143 * object files to satisfy alignments.
2144 * Skip any NULL pointers.
2148 ftrace_record_ip(addr);
2151 /* disable interrupts to prevent kstop machine */
2152 local_irq_save(flags);
2153 ftrace_update_code(mod);
2154 local_irq_restore(flags);
2155 mutex_unlock(&ftrace_lock);
2160 void ftrace_init_module(struct module *mod,
2161 unsigned long *start, unsigned long *end)
2163 if (ftrace_disabled || start == end)
2165 ftrace_convert_nops(mod, start, end);
2168 extern unsigned long __start_mcount_loc[];
2169 extern unsigned long __stop_mcount_loc[];
2171 void __init ftrace_init(void)
2173 unsigned long count, addr, flags;
2176 /* Keep the ftrace pointer to the stub */
2177 addr = (unsigned long)ftrace_stub;
2179 local_irq_save(flags);
2180 ftrace_dyn_arch_init(&addr);
2181 local_irq_restore(flags);
2183 /* ftrace_dyn_arch_init places the return code in addr */
2187 count = __stop_mcount_loc - __start_mcount_loc;
2189 ret = ftrace_dyn_table_alloc(count);
2193 last_ftrace_enabled = ftrace_enabled = 1;
2195 ret = ftrace_convert_nops(NULL,
2201 ftrace_disabled = 1;
2206 static int __init ftrace_nodyn_init(void)
2211 device_initcall(ftrace_nodyn_init);
2213 static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
2214 static inline void ftrace_startup_enable(int command) { }
2215 /* Keep as macros so we do not need to define the commands */
2216 # define ftrace_startup(command) do { } while (0)
2217 # define ftrace_shutdown(command) do { } while (0)
2218 # define ftrace_startup_sysctl() do { } while (0)
2219 # define ftrace_shutdown_sysctl() do { } while (0)
2220 #endif /* CONFIG_DYNAMIC_FTRACE */
2223 ftrace_pid_read(struct file *file, char __user *ubuf,
2224 size_t cnt, loff_t *ppos)
2229 if (ftrace_pid_trace == ftrace_swapper_pid)
2230 r = sprintf(buf, "swapper tasks\n");
2231 else if (ftrace_pid_trace)
2232 r = sprintf(buf, "%u\n", pid_nr(ftrace_pid_trace));
2234 r = sprintf(buf, "no pid\n");
2236 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
2239 static void clear_ftrace_swapper(void)
2241 struct task_struct *p;
2245 for_each_online_cpu(cpu) {
2247 clear_tsk_trace_trace(p);
2252 static void set_ftrace_swapper(void)
2254 struct task_struct *p;
2258 for_each_online_cpu(cpu) {
2260 set_tsk_trace_trace(p);
2265 static void clear_ftrace_pid(struct pid *pid)
2267 struct task_struct *p;
2270 do_each_pid_task(pid, PIDTYPE_PID, p) {
2271 clear_tsk_trace_trace(p);
2272 } while_each_pid_task(pid, PIDTYPE_PID, p);
2278 static void set_ftrace_pid(struct pid *pid)
2280 struct task_struct *p;
2283 do_each_pid_task(pid, PIDTYPE_PID, p) {
2284 set_tsk_trace_trace(p);
2285 } while_each_pid_task(pid, PIDTYPE_PID, p);
2289 static void clear_ftrace_pid_task(struct pid **pid)
2291 if (*pid == ftrace_swapper_pid)
2292 clear_ftrace_swapper();
2294 clear_ftrace_pid(*pid);
2299 static void set_ftrace_pid_task(struct pid *pid)
2301 if (pid == ftrace_swapper_pid)
2302 set_ftrace_swapper();
2304 set_ftrace_pid(pid);
2308 ftrace_pid_write(struct file *filp, const char __user *ubuf,
2309 size_t cnt, loff_t *ppos)
2316 if (cnt >= sizeof(buf))
2319 if (copy_from_user(&buf, ubuf, cnt))
2324 ret = strict_strtol(buf, 10, &val);
2328 mutex_lock(&ftrace_lock);
2330 /* disable pid tracing */
2331 if (!ftrace_pid_trace)
2334 clear_ftrace_pid_task(&ftrace_pid_trace);
2337 /* swapper task is special */
2339 pid = ftrace_swapper_pid;
2340 if (pid == ftrace_pid_trace)
2343 pid = find_get_pid(val);
2345 if (pid == ftrace_pid_trace) {
2351 if (ftrace_pid_trace)
2352 clear_ftrace_pid_task(&ftrace_pid_trace);
2357 ftrace_pid_trace = pid;
2359 set_ftrace_pid_task(ftrace_pid_trace);
2362 /* update the function call */
2363 ftrace_update_pid_func();
2364 ftrace_startup_enable(0);
2367 mutex_unlock(&ftrace_lock);
2372 static struct file_operations ftrace_pid_fops = {
2373 .read = ftrace_pid_read,
2374 .write = ftrace_pid_write,
2377 static __init int ftrace_init_debugfs(void)
2379 struct dentry *d_tracer;
2380 struct dentry *entry;
2382 d_tracer = tracing_init_dentry();
2386 ftrace_init_dyn_debugfs(d_tracer);
2388 entry = debugfs_create_file("set_ftrace_pid", 0644, d_tracer,
2389 NULL, &ftrace_pid_fops);
2391 pr_warning("Could not create debugfs "
2392 "'set_ftrace_pid' entry\n");
2396 fs_initcall(ftrace_init_debugfs);
2399 * ftrace_kill - kill ftrace
2401 * This function should be used by panic code. It stops ftrace
2402 * but in a not so nice way. If you need to simply kill ftrace
2403 * from a non-atomic section, use ftrace_kill.
2405 void ftrace_kill(void)
2407 ftrace_disabled = 1;
2409 clear_ftrace_function();
2413 * register_ftrace_function - register a function for profiling
2414 * @ops - ops structure that holds the function for profiling.
2416 * Register a function to be called by all functions in the
2419 * Note: @ops->func and all the functions it calls must be labeled
2420 * with "notrace", otherwise it will go into a
2423 int register_ftrace_function(struct ftrace_ops *ops)
2427 if (unlikely(ftrace_disabled))
2430 mutex_lock(&ftrace_lock);
2432 ret = __register_ftrace_function(ops);
2435 mutex_unlock(&ftrace_lock);
2440 * unregister_ftrace_function - unregister a function for profiling.
2441 * @ops - ops structure that holds the function to unregister
2443 * Unregister a function that was added to be called by ftrace profiling.
2445 int unregister_ftrace_function(struct ftrace_ops *ops)
2449 mutex_lock(&ftrace_lock);
2450 ret = __unregister_ftrace_function(ops);
2452 mutex_unlock(&ftrace_lock);
2458 ftrace_enable_sysctl(struct ctl_table *table, int write,
2459 struct file *file, void __user *buffer, size_t *lenp,
2464 if (unlikely(ftrace_disabled))
2467 mutex_lock(&ftrace_lock);
2469 ret = proc_dointvec(table, write, file, buffer, lenp, ppos);
2471 if (ret || !write || (last_ftrace_enabled == ftrace_enabled))
2474 last_ftrace_enabled = ftrace_enabled;
2476 if (ftrace_enabled) {
2478 ftrace_startup_sysctl();
2480 /* we are starting ftrace again */
2481 if (ftrace_list != &ftrace_list_end) {
2482 if (ftrace_list->next == &ftrace_list_end)
2483 ftrace_trace_function = ftrace_list->func;
2485 ftrace_trace_function = ftrace_list_func;
2489 /* stopping ftrace calls (just send to ftrace_stub) */
2490 ftrace_trace_function = ftrace_stub;
2492 ftrace_shutdown_sysctl();
2496 mutex_unlock(&ftrace_lock);
2500 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
2502 static atomic_t ftrace_graph_active;
2503 static struct notifier_block ftrace_suspend_notifier;
2505 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
2510 /* The callbacks that hook a function */
2511 trace_func_graph_ret_t ftrace_graph_return =
2512 (trace_func_graph_ret_t)ftrace_stub;
2513 trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
2515 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
2516 static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
2520 unsigned long flags;
2521 int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
2522 struct task_struct *g, *t;
2524 for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
2525 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
2526 * sizeof(struct ftrace_ret_stack),
2528 if (!ret_stack_list[i]) {
2536 read_lock_irqsave(&tasklist_lock, flags);
2537 do_each_thread(g, t) {
2543 if (t->ret_stack == NULL) {
2544 t->curr_ret_stack = -1;
2545 /* Make sure IRQs see the -1 first: */
2547 t->ret_stack = ret_stack_list[start++];
2548 atomic_set(&t->tracing_graph_pause, 0);
2549 atomic_set(&t->trace_overrun, 0);
2551 } while_each_thread(g, t);
2554 read_unlock_irqrestore(&tasklist_lock, flags);
2556 for (i = start; i < end; i++)
2557 kfree(ret_stack_list[i]);
2561 /* Allocate a return stack for each task */
2562 static int start_graph_tracing(void)
2564 struct ftrace_ret_stack **ret_stack_list;
2567 ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
2568 sizeof(struct ftrace_ret_stack *),
2571 if (!ret_stack_list)
2575 ret = alloc_retstack_tasklist(ret_stack_list);
2576 } while (ret == -EAGAIN);
2578 kfree(ret_stack_list);
2583 * Hibernation protection.
2584 * The state of the current task is too much unstable during
2585 * suspend/restore to disk. We want to protect against that.
2588 ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
2592 case PM_HIBERNATION_PREPARE:
2593 pause_graph_tracing();
2596 case PM_POST_HIBERNATION:
2597 unpause_graph_tracing();
2603 int register_ftrace_graph(trace_func_graph_ret_t retfunc,
2604 trace_func_graph_ent_t entryfunc)
2608 mutex_lock(&ftrace_lock);
2610 ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
2611 register_pm_notifier(&ftrace_suspend_notifier);
2613 atomic_inc(&ftrace_graph_active);
2614 ret = start_graph_tracing();
2616 atomic_dec(&ftrace_graph_active);
2620 ftrace_graph_return = retfunc;
2621 ftrace_graph_entry = entryfunc;
2623 ftrace_startup(FTRACE_START_FUNC_RET);
2626 mutex_unlock(&ftrace_lock);
2630 void unregister_ftrace_graph(void)
2632 mutex_lock(&ftrace_lock);
2634 atomic_dec(&ftrace_graph_active);
2635 ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
2636 ftrace_graph_entry = ftrace_graph_entry_stub;
2637 ftrace_shutdown(FTRACE_STOP_FUNC_RET);
2638 unregister_pm_notifier(&ftrace_suspend_notifier);
2640 mutex_unlock(&ftrace_lock);
2643 /* Allocate a return stack for newly created task */
2644 void ftrace_graph_init_task(struct task_struct *t)
2646 if (atomic_read(&ftrace_graph_active)) {
2647 t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
2648 * sizeof(struct ftrace_ret_stack),
2652 t->curr_ret_stack = -1;
2653 atomic_set(&t->tracing_graph_pause, 0);
2654 atomic_set(&t->trace_overrun, 0);
2656 t->ret_stack = NULL;
2659 void ftrace_graph_exit_task(struct task_struct *t)
2661 struct ftrace_ret_stack *ret_stack = t->ret_stack;
2663 t->ret_stack = NULL;
2664 /* NULL must become visible to IRQs before we free it: */
2670 void ftrace_graph_stop(void)